Chemical solution application apparatus and chemical solution application method

ABSTRACT

An object is to provide a chemical solution application apparatus capable of applying a chemical solution evenly and without irregularity by a spin coating method. A plurality of nozzles are provided for applying a chemical solution to an application object that is fixed over a stage. Each of the nozzles is individually mobile in vertical and horizontal directions. For this reason, controlling a discharging point or pattern is possible, and application responding to a wider viscosity range of chemical solutions is possible. By implementing the present invention, a chemical solution application apparatus equipped with a discharging method of a chemical solution by which a coating film having a small film thickness distribution over an entire substrate and an even thickness can be obtained, as well as for which use efficiency is improved by cutting down on waste of a chemical solution to be discharged.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a chemical solution applicationapparatus and a chemical solution coating method for applying a chemicalsolution to an application object.

2. Description of the Related Art

A chemical solution application apparatus typified by a conventionalspin coater apparatus forms a thin film over a substrate surface byfixing the substrate on a rotating disk, continually dripping dropletsfrom a single nozzle to a single central spot of the substrate surfaceor to a plurality of spots, and rotating the rotating disk (for example,refer to Patent Document 1: Japanese Patent Laid-Open No. H6-15224).

Also, an apparatus that applies a liquid from a plurality of nozzles isbeing devised, in response to size increase in substrates or for thepurpose of using several kinds of chemical solutions. A photoresist canbe spread evenly over a whole top surface of a substrate by movingnozzles in which a plurality of dripping holes are linearly arranged aseach dripping hole drips the photoresist so as to drip the photoresistover the entire top surface of the substrate, and rotating a turntableby driving a motor so that the substrate turns in the surface direction(for example, refer to Patent Document 2: Japanese Patent Laid-Open No.H8-141477).

SUMMARY OF THE INVENTION

However, in an application method that continuously drips droplets froma single nozzle to a plurality of spots, an application cannot be evenover a substrate since a fluid coloring resin that is discharged earlierdries and a film thickness of a region to which the fluid coloring resinis discharged earlier becomes thick, while the nozzle is being moved.

Also, a dripping method, where a nozzle in which a plurality of drippingholes arranged linearly is unidirectionally moved linearly andrelatively, is appropriate when a substrate has a square-form and thesize is specified; however, when application is done on a round-formsubstrate or on substrates with different sizes, wasting of a dischargematerial occurs. Resists are expensive, and should not be wasted.Further, in a similar manner to the case of a single nozzle, while theplurality of nozzles arranged linearly is moved, a discharge materialdischarged earlier gradually dries; therefore, by the time ofsubsequently rotating a turntable by driving a motor, viscosity changesbetween the first and last regions the discharge material is dripped,and irregular application occurs.

When the type (viscosity) of a chemical solution to be discharged ischanged, the way the chemical solution coats an application object alsochanges significantly. In the case of low viscosity, the chemicalsolution is spinned off before the entire surface of a substrate iscoated evenly. In the case of high viscosity, there is a case where thechemical solution does not spread and coat the entire surface.Therefore, in order to obtain an even coating film, selecting dischargepoints with respect to the substrate is important. However, for a nozzlein which a plurality of dripping holes are arranged linearly, there is aproblem that a discharge point pattern cannot be selected.

In view of the foregoing problem, an object of the present invention isto provide a chemical solution discharging method and a chemicalsolution application apparatus by which a coating film having an eventhickness and a small film thickness distribution over an entire surfacecan be obtained. Also, an object is to provide a chemical solutiondischarging method and a chemical solution application apparatus whichavoid wasting a chemical solution to be discharged and for which useefficiency is improved.

One feature of a structure of the present invention includes a stageholding a substrate; a plurality of nozzles provided facing thesubstrate held by the stage and which discharge a chemical solution onthe substrate; a driving mechanism that freely moves each of theplurality of nozzles; and a control portion that controls an amount ofchemical solution that is discharged from the plurality of nozzles.

One feature of a structure of the present invention includes a stageholding a substrate; a plurality of nozzles provided facing thesubstrate held by the stage and which discharge a chemical solution onthe substrate; a first driving mechanism that freely moves each of theplurality of nozzles; a second driving mechanism that moves the stage;and a control portion that controls an amount of chemical solution thatis discharged from the plurality of nozzles.

One feature of a structure of the present invention includes a stageholding a substrate; a plurality of nozzles provided facing thesubstrate held by the stage and which discharge a chemical solution onthe substrate; a first driving mechanism that freely moves each of theplurality of nozzles; a second driving mechanism that moves the stage; atank storing the chemical solution; and a control portion attached tothe tank via a piping and controls an amount of chemical solution thatis discharged from the plurality of nozzles.

One feature of a structure of the present invention includes a stageholding a substrate; a guide rail provided facing the substrate held bythe stage; a plurality of nozzles held by the guide rail, that dischargea chemical solution on the substrate; a tank storing the chemicalsolution; and a control portion attached to the tank via a piping andcontrols an amount of chemical solution that is discharged from theplurality of nozzles; wherein the plurality of nozzles are each capableof freely moving along the guide rail.

In the foregoing one feature of a structure of the present invention,the guide rail is arranged in a matrix form.

One feature of a structure of the present invention is equipped with astage holding a substrate; a guide rail provided facing the substrateheld by the stage; a plurality of nozzles held by the guide rail, thatdischarge a chemical solution on the substrate; a tank storing thechemical solution; and a control portion attached to the tank via apiping and controls an amount of chemical solution that is dischargedfrom the plurality of nozzles; wherein each of the plurality of nozzlesis freely moved and arranged in a prescribed position along the guiderail, and a chemical solution is discharged from the plurality ofnozzles to the substrate held over the stage.

In the foregoing one feature of a structure of the present invention,the plurality of nozzles can move in a vertical direction with respectto an application object.

In the foregoing one feature of a structure of the present invention,all of the plurality of nozzles need not be used, and the number ofnozzles used can be changed depending on the size of a substrate, theviscosity of a chemical solution, and the like.

In one feature of the present invention, a chemical solution dischargedfrom a/the plurality of nozzles is not limited to one type. Severalkinds of chemical solutions are filled in each tank, and by changing thenozzles selected at a time of discharge, a coating film can be formedcontinuously.

As a chemical solution discharged in the present invention, an organicresin such as an acrylic resin, a polyimide resin, a melamine resin, apolyester resin, a polycarbonate resin, a phenol resin, an epoxy resin,polyacetal, polyether, polyurethane, polyamide (nylon), polyimide-amide,a fran resin, or a diallyl phthalate resin; or, siloxane, polysilazane,or hexamethyldisilazane, can be used. Alternatively, a solution using apolar solvent such as water, alcohol, ether, dimethylformamide,dimethylacetamide, dimethylsulfoxide, N-methylpyrrolidon,hexamethylphosphamide, chloroform, or methylene chloride, can be used.Further, a resist such as a diazonaphthoquinone-novolac resin series(developing solution is TMAH (Tetramethylammonium hydroxide)),polymethylmethacrylate (developing solution is a solution ofmethylisobutylketone:isopropyl alcohol=1:3), or a copolymer ofalphamethylstyrene-alphachloroacrylic acid (developing solution is amixed xylene) can be used. Also, a silane coupling agent such as FAS(fluoroalkylsilane) can be used. Needless to say, the chemical solutionis not limited to the chemical solutions listed above, and a variety ofchemical solutions can be used depending on the purpose.

By implementing the present invention, a chemical solution applicationapparatus equipped with a discharging method can be obtained, by which acoating film having an even thickness and a small film thicknessdistribution over an entire surface can be obtained, and for which useefficiency can be improved by cutting down on waste of a chemicalsolution to be discharged.

A resist which is one discharge material is expensive. However, it issaid that during ordinary spin coating, 97% of a resist dripped on awafer spatters. Therefore, by using a chemical solution applicationapparatus of the present invention having a driving mechanism capable offreely moving each of a plurality of nozzles, a most appropriate amountcan be discharged in a most appropriate place, and use efficiency of aresist can be drastically improved.

When a substrate is large and rectangular, by also positioning nozzlesin edge portions of the substrate, spinning off of a chemical solutiondoes not occur in the four corners of the substrate, and forming an evencoating film even on a large-sized substrate becomes possible.

BRIEF DESCRIPTION OF DRAWINGS

In the accompanying drawings:

FIG. 1 shows a cross-sectional view describing a structure of a chemicalsolution application apparatus of the present invention;

FIGS. 2A and 2B each show a top view of a chemical solution applicationapparatus of the present invention;

FIG. 3 shows a perspective view of a chemical solution applicationapparatus of the present invention;

FIGS. 4A and 4B show a case of using a chemical solution applicationmethod of the present invention for a crystallization technique;

FIGS. 5A and 5B show manufacturing an EL light emitting element usingthe present invention;

FIG. 6 shows a typical structure of a light emitting element;

FIGS. 7A and 7B show a top view and a cross-sectional view,respectively, of a manufacturing process of a pixel portion in a displaydevice to which the present invention is applied;

FIGS. 8A and 8B show a top view and a cross-sectional view,respectively, of a manufacturing process of a pixel portion in a displaydevice to which the present invention is applied;

FIGS. 9A and 9B show a top view and a cross-sectional view,respectively, of a manufacturing process of a pixel portion in a displaydevice to which the present invention is applied;

FIGS. 10A to 10E each show a cross-sectional view of a manufacturingprocess of a pixel portion in a display device to which the presentinvention is applied;

FIGS. 11A and 11B show a top view and a cross-sectional view,respectively, of a manufacturing process of a pixel portion in a displaydevice to which the present invention is applied;

FIGS. 12A and 12B show a top view and a cross-sectional view,respectively, of a manufacturing process of a pixel portion in a displaydevice to which the present invention is applied;

FIGS. 13A and 13B show a top view and a cross-sectional view,respectively, of a manufacturing process of a pixel portion in a displaydevice to which the present invention is applied;

FIGS. 14A to 14C each show a cross-sectional view of a manufacturingprocess of a pixel portion in a display device to which the presentinvention is applied;

FIG. 15 shows a perspective view describing a liquid crystal dripinjection method employing a dispenser method;

FIGS. 16A to 16D each show an electrical appliance to which the presentinvention is applied; and

FIG. 17 shows a perspective view of a chemical solution applicationapparatus of the present invention.

DETAILED DESCRIPTION OF THE INVENTION Embodiment Modes

Although the present invention will be described by way of embodimentmodes with reference to the accompanying drawings, it is to beunderstood that various changes and modifications will be apparent tothose skilled in the art. Therefore, unless such changes andmodifications depart from the scope of the invention, they should beconstrued as being included therein.

Embodiment Mode 1

First, a chemical solution application apparatus equipped with aplurality of mobile nozzles is described using FIG. 1 and FIGS. 2A and2B. FIG. 1 is a side view of a chemical solution application apparatusof the present invention, and FIGS. 2A and 2B are top views. A substrate102 is set over a suction stage 101 (also called a rotation supportingboard or turntable). Also, a plurality of mobile nozzles 103(a) to (d)are fixed on a guide rail 106 (abbreviated in FIGS. 2A and 2B). Each ofthe nozzles 103(a) to (d) can change directions along an x axis, a yaxis, and a z axis, and are connected to chemical solution pumpingportions (tanks) 105(a) to (d) through pipings 104(a) to (d). Betweenthe plurality of nozzles 103 and the tanks 105, chemical solutiondischarge control mechanisms (also called discharge controlling means orcontrol portions) 109(a) to (d) are connected to control them. Further,each of the tanks 105(a) to (d) which has received a signal from thechemical solution discharge control mechanisms 109(a) to (d) adjusts itschemical solution pumping by the signal, and discharges a chemicalsolution of a prescribed amount from each of the nozzles 103(a) to (d).By the chemical solution discharge control mechanisms 109(a) to (d), adischarging amount and a discharging speed can be changed depending onthe position and shape of a substrate. Further, a cup 107 and a cup lid108 are set so that a chemical solution does not spatter out while thesubstrate 102 is rotating and so that the chemical solution that hasbecome a mist is prevented from reattaching to the substrate 102 bycontrolling airflow in the cup 107 (see FIG. 1).

The tanks 105(a) to (d) may be provided between each of the nozzles103(a) to (d) and the chemical solution discharge control mechanisms109(a) to (d). Also, if a mechanism for adjusting chemical solutionpumping is provided on each of the tanks 105(a) to (d) itself, thechemical solution discharge control mechanisms 109(a) to (d) are notnecessarily provided.

The tanks 105(a) to (d) and the chemical solution discharge controlmechanisms 109(a) to (d) need not be provided for each of the nozzles103(a) to (d), and as shown in FIG. 2B, a single chemical solutiondischarge control mechanism 209 and a single tank 205 may be provided.

For the stage, a driving mechanism which moves the stage in vertical andhorizontal directions may be provided. Also, as a substrate holdingmethod instead of the stage, a spin chuck employing a mechanical chucksystem may be used. Note that in FIGS. 1, 2A and 2B, the substrate 102is shown to be larger than the stage 101; however, the stage 101 may belarger.

The distance between the substrate 102 and the mobile nozzles 103(a) to(d) can be adjusted by moving the substrate in a vertical direction.

Note that the plurality of mobile nozzles 103(a) to (d) may be movedautomatically or manually. When it is automatic, the plurality ofnozzles can be freely moved by providing a driving mechanism capable ofindividually moving them. FIG. 3 shows a perspective view of a chemicalsolution application apparatus of a case where the nozzles are movedmanually. Over a substrate (application object) 302 fixed on a turntable301, a guide rail 306 are arranged in a grid. Under the guide rail 306,a plurality of nozzles 303 are fixed by a jig. Each of the nozzles 303can be made to discharge by manually moving it in a direction shown byarrows and changing a position where it is fixed. At this time, bymaking the grid fine, a degree of freedom in arranging the nozzlesincreases.

Note that the plurality of the mobile nozzles are not necessarily allused at the same time. A nozzle in a necessary spot can be run todischarge on a case-by-case basis depending on a size of a substrate oran amount or viscosity of a chemical solution. Further, a chemicalsolution to be used in a subsequent coating film can be put in a tankconnected to a remaining nozzle, and a coating film may be formedcontinually. As a result, throughput can be improved.

Note that in FIGS. 1 to 2B, only four nozzles are shown; however, itgoes without saying that it is not limited to this number. The number ofnozzles may be any as long as it is 2 or more. The number may be decideddepending on a size of a substrate or viscosity of a chemical solutionto be applied. For example, the number of nozzles may be a number foundby a multiplication of the number of rows and the number of columns (n×m(n, m>0)), as shown in FIG. 3. Also, the number does not need to be anumber that can be found by the multiplication, and the number ofnozzles may be five like in a chemical solution application apparatusshown in FIG. 17.

In the present invention, every time a substrate or a chemical solutionis changed, an arrangement of the nozzles can be changed depending on asize of the substrate, viscosity of the chemical solution, and howeasily the chemical solution dries. For example, for a rectangular,large substrate, the nozzles are moved and arranged also in the fourcorners. For example, for a chemical solution that easily dries, thenozzles are moved and arranged evenly over the entire substrate. In thismanner, since each of the plurality of nozzles can move freely, acoating film that is even over an entire substrate can be formed byfinely adjusting an arrangement of the nozzles depending on a size ofthe substrate, viscosity of a chemical solution, or the like.

Embodiment Mode 2

This embodiment mode is described using FIGS. 7A to 15. Morespecifically, a manufacturing method of a display device (which means aliquid crystal display device herein) to which the present invention isapplied is described. First, a manufacturing method of a display deviceincluding a channel-etch type thin film transistor, to which the presentinvention is applied is described. Figures A of FIGS. 7 to 9 and FIGS.11 to 13 each show a top view of a display device pixel portion, and thefigures B of FIGS. 7 to 9 and FIGS. 11 to 13 each show a cross-sectionalview of the figures A of FIGS. 7 to 9 and FIGS. 11 along lines G-H.

Over a substrate 700, a base film 701 is formed as a base pretreatment.For the substrate 700, a glass substrate made from barium borosilicateglass, alumino borosilicate glass, or the like; a quartz substrate; asilicon substrate; a metal substrate; a stainless steel substrate; or aplastic substrate having heat resistance that can resist a treatmenttemperature of the present manufacturing process is used. Also, asurface of the substrate 700 may be polished by a CMP (chemicalmechanical polishing) method or the like so that the surface isplanarized. Note that an insulating layer may be formed over thesubstrate 700. The insulating layer is formed using at least one of anoxide material containing silicon and a nitride material, as a singlelayer or as a lamination. This insulating layer is not necessary to beformed; however, it has an effect of shutting off a contaminant from thesubstrate 700. This insulating layer can be formed using a chemicalsolution application apparatus of the present invention. The insulatinglayer can be formed to have an even film thickness by setting an optimaldischarging pattern that accommodates to a viscosity of a material ofthe insulating film. In a case of forming a base layer for preventingcontamination from a glass substrate, the base film 701 is formed as thebase pretreatment for a gate electrode layer 703 to be formed thereoverby a droplet discharging method. Note that the droplet dischargingmethod refers to a method of forming the base film 701 and the gateelectrode layer 703 or the like in an arbitrary location by selectivelydischarging (jetting) droplets (also called “dots”) of a compositionincluding a material for a conductive film, an insulating film, or thelike. Depending on its system, the droplet discharging method may referto discharging by an inkjet device.

In this embodiment mode, a substance having low wettability is formed asthe base film 701 (see FIGS. 7A and 7B). This base film 701 can also beformed using the chemical solution application apparatus of the presentinvention. The base film can be formed to have an even film thickness bysetting an optimal discharging pattern that accommodates to a viscosityof a material of the base film.

Subsequently, a modification treatment is carried out on the base filmby irradiating a region in which the gate electrode layer is to beformed with a laser light 771 a by a laser device (see FIGS. 8A and 8B).By this modification treatment, base films 702 a and 702 b becomeregions having higher wettability with respect to a compositionincluding a conductive material for forming the gate electrode layer tobe laminated thereover. Consequently, a difference in the degree ofwettability occurs between the base films 702 a and 702 b and aperipheral base film, with respect to the composition including aconductive material.

Wettability is explained herein. High wettability means having highlyophilic property (low repellent property), and when a liquidcomposition having fluidity is formed on a surface of a region havinghigh wettability, a contact angle of the liquid composition havingfluidity becomes small. When the contact angle is small, the liquidcomposition having fluidity expands over a surface and wets the surfacewell. On the contrary, low wettability means having a high repellentproperty (low lyophilic property), and when the liquid compositionhaving fluidity is formed on a surface of a region having lowwettability, a contact angle of the liquid composition having fluiditybecomes large. When the contact angle is large, the liquid compositionhaving fluidity does not expand over a surface of a region and isrepelled, and does not wet the surface. A region having a differentwettability has a different surface energy. A surface energy of asurface of a region having high wettability is large, and a surfaceenergy of a surface of a region having low wettability is small. Acontact angle of a liquid composition having fluidity formed on a regionhaving high wettability is preferably 30 degrees or less, and a contactangle of a liquid composition having fluidity formed on a region havinglow wettability is preferably 90 degrees or more.

In regions of the base films 702 a and 702 b for which a modificationtreatment has been carried out by laser light, the gate electrode layer703 and a capacitor wiring layer 704 are formed by discharging dropletsof a composition including a conductive material by a dropletdischarging apparatus 780 a (see FIGS. 9A and 9B). Over the base film701, the discharged droplets are formed in the regions of the base films702 a and 702 b. which have higher wettability than a surroundingregion. Even in a case where sizes of discharging openings of nozzles bywhich droplets are discharged are larger than a desired size of aconductive layer to be formed, by applying a treatment for increasingwettability to a formation region of the conductive layer, the dropletsonly adhere to the formation region, and the conductive layer is formedto be a thin line. This is because, since a difference in a degree ofwettability is made to occur between the formation region and aperipheral region, the droplets are repelled in the peripheral regionand stay in the formation region having a higher wettability.

By carrying out a modification by irradiating a treatment object withlaser light, when a fine pattern is to be formed like the gate electrodelayer 703, the droplets do not expand over the formation region and canbe in a thin line even if a discharge opening of droplets is somewhatlarge. Also, by controlling a liquid amount of the droplets, controllinga film thickness of the conductive layer is also possible. Since laserlight is capable of fine processing, by carrying out a modification of afilm by laser light irradiation, a fine wiring, an electrode, and thelike can be formed with good controllability.

Note that when the base film 701 formed as a base pretreatment is to beformed using a chemical solution application apparatus of the presentinvention, and when it is necessary to remove a solvent, baking ordrying may be carried out.

The base film 701 may be formed with a thickness of 0.01 to 10 nm;however, since it is acceptable as long as it is formed to be extremelythin, having a layer structure is not always necessary. In a case wherea metal material or a 3d transition metal element is used as the basefilm and when the base film has a conductive property, for a base filmother than a conductive layer formation region, it is desirable to carryout the following two methods.

As a first method, an insulating layer is formed by making the base film701 that does not overlap with the gate electrode layer 703 (in otherwords, a peripheral region having a lower wettability) to be insulating.In other words, the base film 701 that does not overlap with the gateelectrode layer 703 is oxidized to make it insulating. In this manner,in a case of making the base film 701 that does not overlap with thegate electrode layer 703 to be insulating by oxidization, it ispreferably formed to have a thickness of 0.01 to 10 nm since oxidationcan easily be done. As a method of oxidation, a method of exposing thebase film 701 that does not overlap with the gate electrode layer 703under an oxygen atmosphere may be used, or a method of carrying out aheat treatment may be used.

As a second method, an insulating layer is selectively formed in aformation region of the gate electrode layer 703 (a region to which acomposition including a conductive material is discharged). The basefilm 701 that does not overlap with the gate electrode layer 703 may beselectively formed over a substrate using a droplet discharging methodor the like, or by forming over an entire surface of the substrate by anapplication method of the present invention, and then selectivelyetching away and removing the base film 701 with the gate electrodelayer 703 as a mask. When using this process, a thickness of the basefilm 701 is not restricted.

Further, as another method, an organic material based substance thatfunctions like an adhesive material may be formed in order to increaseadhesion of a pattern to be formed by a droplet discharging method and aformation region thereof. An organic material (organic resin material)(polyimide, acrylic), or an organic group (for example, an alkyl groupor an aromatic hydrocarbon) including at least hydrogen for asubstituent group and for which a skeleton structure is formed by a bondbetween silicon (Si) and oxygen (O), is used. A fluoro group may be usedas the substituent group. Alternatively, as the substituent groups, anorganic group including at least hydrogen and a fluoro group may beused.

Formation of the gate electrode layer 703 and the capacitor wiring layer704 is carried out using a droplet discharging means. The dropletdischarging means is a collective term for means of dischargingdroplets, such as a head having a nozzle with a discharge opening for acomposition, and a head with one or a plurality of nozzles.

As a base pretreatment for a conductive layer formed using a dropletdischarging method, the aforementioned process of forming the base film701 is carried out; however, this treatment process may be carried outafter forming the gate electrode layer 703 and the capacitor wiringlayer 704.

Also, after the gate electrode layer 703 and the capacitor wiring layer704 are formed by discharging a composition by a droplet dischargingmethod, a surface of the gate electrode layer 703 and the capacitorwiring layer 704 may be planarized by pressing with pressure in order toincrease planarity. As a method of pressing, asperity may be evened outand reduced by scanning a roller-like object over the surface, or thesurface may be pressed vertically with a flat, board-like object. Aheating process may be carried out during pressing. Further, an asperityportion of the surface may be removed by an air knife after softening ormelting the surface with a fluxing material or the like. Also, thesurface may be polished using a CMP method. This process can be appliedto in a case where asperity occurs due to a droplet discharging methodand when the surface is to be planarized. As a result, a wiring with aline width of 5 μm or less is formed as the gate electrode layer.

Subsequently, a gate insulating layer 705 is formed over the gateelectrode layer 703 and the capacitor wiring layer 704 (see FIG. 10A).The gate insulating layer 705 may be formed with a known material suchas a silicon oxide material or a silicon nitride material and may be asingle layer or a lamination layer. In this embodiment mode, a threelayer lamination of a silicon nitride film, a silicon oxide film, and asilicon nitride film. Alternatively, the gate insulating layer 705 mayhave a single layer of silicon oxynitride film or two layers thereof.Preferably, a dense silicon nitride film is used. When using silver,copper or the like for the conductive layers formed by a dropletdischarging method, diffusion of an impurity is prevented and a surfaceof the conductive layer is planarized by forming a silicon nitride filmor a NiB film thereover as a barrier film. In order to form a denseinsulating film with little gate leakage current at a low film formingtemperature, a reactive gas containing a rare gas element such as argonmay be mixed into the insulating film to be formed.

Next, a semiconductor film is formed. A semiconductor layer having oneconductivity type may be formed as necessary. In this embodiment mode, asemiconductor layer 706, and an N-type semiconductor layer 707 as asemiconductor layer having one conductivity type, are laminated (seeFIG. 10B). Note that a P channel type TFT for which a P typesemiconductor layer is formed instead of an N type semiconductor layercan be formed. Further, a CMOS structure formed with an N channel typeTFT and a P channel type TFT can also be manufactured. Also, in order togive conductivity, by forming an impurity region in the semiconductorlayer by adding an element giving conductivity through doping, anN-channel type TFT and a P-channel type TFT can be formed.

In this embodiment mode, an amorphous semiconductor is used as asemiconductor. After a semiconductor layer is formed, an N-typesemiconductor layer is formed as a semiconductor layer having oneconductivity type by a plasma CVD method or the like.

Subsequently, a Nega-type resist 740 is applied over the N-typesemiconductor layer 706 using a chemical solution application apparatusof the present invention (see FIG. 10C). As a commercial resist materialincluding a photosensitizer, a base resin, diphenylsilanediol, an acidgenerator, and the like which are Nega-type resists, can be used. APosi-type resist may be used instead of a Nega-type resist, and forexample, a typical positive type resist such as a novolac resin or anaphthoquinone diazide compound that is a photosensitizer can be used.Further, as a mask replacing a resist, a resin material such as an epoxyresin, an acrylic resin, a phenol resin, a novolac resin, a melamineresin, or an urethane resin is used. Furthermore, an organic materialsuch as benzocyclobutene, parylene, allylene ether fluoride, or apermeable polyimide; a compound material made by polymerization of asiloxane based polymer or the like; a composition material including awater-soluble homopolymer and a water-soluble copolymer; or the like maybe used. In using any of the materials, surface tension and viscositythereof are appropriately adjusted by adjusting a concentration of asolvent and/or by adding a surfactant or the like.

Next, a portion in which the resist is to be left is irradiated withlight (see FIG. 10D). Subsequently, a mask 741 is formed by removing theresist that is not exposed to light, by a developing treatment. Then,the semiconductor layer 706 and the N-type semiconductor layer 707 areformed by simultaneously patterning a semiconductor layer and an N-typesemiconductor layer using the mask 741 (see FIG. 10E). Note that themask can be formed by selectively discharging a composition. In theabove manner, the semiconductor layer 706 and the N-type semiconductorlayer 707 are formed (see FIGS. 11A and 11B).

Also, in this embodiment mode, as a pretreatment when the gate electrodelayer 703 and the capacitor wiring layer 704 are formed by a dropletdischarging method, a pattern can be selectively formed, like how a basefilm is formed and then a modification treatment by laser lightirradiation is carried out. When the pattern is formed by dischargingdroplets by a droplet discharging method, a modification treatment canbe carried out on a pattern formation region by a laser lightirradiation treatment. By carrying out this modification treatment onlyin the formation region, a difference in wettability occurs between theformation region and a peripheral region thereof, and the pattern can beformed with good controllability since the droplets stay only in theformation region having high wettability.

Source/drain electrode layers 730 and 708 are formed by discharging acomposition including a conductive material, and the semiconductor layer706 and the N-type semiconductor layer 707 are patterned using thesource/drain electrode layers 730 and 708 as masks, so that thesemiconductor layer 706 is exposed (see FIGS. 12A and 12B). Thesource/drain electrode layers 730 and 708 can be formed in a similarmanner to how the aforementioned gate electrode layer 703 is formed. Thesource/drain electrode layer 730 also functions as a wiring layer.

As a conductive material forming the source/drain electrode layers 730and 708, a composition mainly containing particles of a metal such as Ag(silver), Au (gold), Cu (copper), W (tungsten), or Al (aluminum) Also,indium tin oxide (ITO) having a light transmitting property, indium tinoxide including silicon oxide (ITSO), organic indium, organic tin, zincoxide, titanium nitride, and the like may be combined.

Also, as a base pretreatment for a conductive layer formed using adroplet discharging method, the aforementioned process for forming abase film is carried out; furthermore, this treatment process may becarried out after the conductive layer is formed. By this process,adhesiveness between layers improves; therefore, reliability of adisplay device can also be improved.

Subsequently, a pixel electrode layer 711 is selectively formed over thegate insulating layer 705 so as to be in contact with the source/drainelectrode layer 708, by discharging a composition including a conductivematerial (see FIGS. 13A and 13B). In a case of manufacturing atransmissive type liquid crystal display panel, the pixel electrodelayer 711 may be formed by forming a prescribed pattern with acomposition including at least one of indium tin oxide (ITO), indium tinoxide including silicon oxide (ITSO), zinc oxide (ZnO), tin oxide (SnO₂)and the like, and then by baking.

The pixel electrode layer 711 can also be selectively formed over thegate insulating layer 705 before forming the source/drain electrodelayer 708. In this case, in this embodiment mode, a connection structureof the source/drain electrode layer 708 and the pixel electrode layer711 is a structure of laminating the source/drain electrode layer 708over the pixel electrode layer. By forming the pixel electrode layer 711before forming the source/drain electrode layer 708, a flat formationregion can be formed; therefore, coatability is good, and the pixelelectrode layer 711 can be formed with good flatness since a polishingtreatment such as CMP can be carried out sufficiently.

Also, as shown in FIGS. 14A to 14C, an insulator 750 that is to be aninterlayer insulating layer may be formed over the source/drainelectrode layer 708 so as that the source/drain electrode layer 708 iselectrically connected to the pixel electrode layer 711 via a wiringlayer 752. In this case, an opening portion (contact hole) is not formedby removing the insulator 750, but a substance 751 having lowwettability with respect to the insulator 750 is formed over thesource/drain electrode layer 708. Subsequently, when a compositionincluding the insulator 750 is applied by an application method or thelike, the insulator 750 is formed in a region excluding a region wherethe low wettability substance 751 is formed (see FIG. 14A).

After the insulator 750 is solidified by heating, drying or the like,the low wettability substance 751 is removed, and the opening portion isformed. The wiring layer 752 is formed so as to fill in this openingportion, and the pixel electrode layer 711 is formed so as to be incontact with this wiring layer 752 (see FIG. 14B). By using this method,it is not necessary to form the opening portion by etching; therefore,there is an effect that a process is simplified.

Also, in a case of forming the insulator 750 that is to be an interlayerinsulating layer over the source/drain electrode layer 708 as in FIGS.14A and 14B, another formation method of the opening portion can beused. In this case, a photosensitive insulator is used for the insulator750. After the photosensitive insulator is formed as the interlayerinsulating layer, a region thereof in which the opening potion is to beprovided is irradiated with laser light, so that the insulator in thatthe region is exposed to light. The insulator exposed to light isremoved by etching or the like, and the opening portion (contact hole)reaching the source/drain electrode layer 708 is formed. A conductivelayer is formed in this opening portion so as to be connected to thesource/drain electrode layer 708, and a first electrode layer is formedso as to be connected to this conductive layer. In this embodiment mode,since modification and treatment processes by laser light irradiationare carried out, fine processing can be realized.

Further, the pixel electrode layer 711 is preferably formed of indiumtin oxide (ITO), indium tin oxide including silicon oxide (ITSO), zincoxide (ZnO), or the like by a sputtering method. More preferably, thepixel electrode layer 711 is formed using indium tin oxide includingsilicon oxide, by a sputtering method using a target of ITO including 2to 10 wt % silicon oxide. Other than this, an oxide conductive materialincluding silicon oxide, and in which 2 to 20 wt % zinc oxide (ZnO) ismixed in indium oxide, may be used. After forming the pixel electrodelayer 711 by a sputtering method, a mask layer may be formed by adroplet discharging method and then etching the pixel electrode layer711 into a desired pattern. In this embodiment mode, the pixel electrodelayer 711 is formed of a conductive material having a light transmittingproperty using a droplet discharging method. Specifically, the pixelelectrode layer 711 is formed using indium tin oxide, or ITSOconstituted by ITO and silicon oxide.

Also, in a case of manufacturing a reflective type liquid crystaldisplay panel, a composition mainly including particles of a metal suchas Ag (silver), Au (gold), Cu (copper), W (tungsten), or Al (aluminum)can be used. As another method, the pixel electrode layer 711 may beformed by forming a transparent conductive film or a light reflectingconductive film by a sputtering method, forming a mask pattern by adroplet discharging method, and then combining an etching process.

The pixel electrode layer 711 may be swabbed and polished by a CMPmethod and by using a polyvinyl alcohol based porous body so that thesurface is planarized. Also, after polishing using a CMP method,ultraviolet light irradiation, oxygen plasma treatment and the like maybe carried out on a surface of the pixel electrode layer 711.

By the above process, a substrate 700 having a TFT for a display panel(liquid crystal display panel), in which a bottom gate type (also called“reverse stagger type”) TFT is connected to a pixel electrode over thesubstrate 700 is completed. Further, a TFT of this embodiment mode is achannel-etch type.

Subsequently, as shown in FIG. 14C, an insulating layer 712 functioningas an orientation film is formed so as to cover the pixel electrodelayer 711, by a chemical solution application method of the presentinvention. FIG. 14C is a cross-sectional view of the top view figures Ashown in FIGS. 7 to 9 and 11 to 13 along lines G to H, as well as acompletion drawing of a display panel. Note that the insulating layer712 can be selectively formed by using a screen printing method or anoffset printing method. Rubbing is carried out thereafter. Subsequently,a sealant is formed by a droplet discharging method in a peripheralregion of where a pixel is formed (not shown in the figure).

Subsequently, a display panel (liquid crystal display panel) can bemanufactured by sticking together an opposing substrate 724, for whichthe insulating layer 712 functioning as an orientation film, a coloringlayer 722 functioning as a color filter, a conductive layer 723functioning as an opposing electrode, and a polarizing plate 725 areprovided, and the substrate 700 having a TFT via a spacer, and byproviding a liquid crystal layer 720 in an air gap thereof (see FIG.14C). A filler may be mixed in the sealant, and further, a shieldingfilm (black matrix) or the like may be formed for the opposing substrate724. Note that as a method of forming a liquid crystal layer, adispenser method (dripping method) or a dip method (pumping method) inwhich a liquid crystal is injected using the capillary phenomenon, aftersticking together the opposing substrate 724 with the substrate 700, canbe used.

A liquid crystal drip injection method employing a dispenser method isdescribed using FIG. 15. In FIG. 15, reference numerals 40, 42, 43, 33,34, 32, 30, and 20 represent a control device, an imaging means, a head,a liquid crystal, a barrier layer, a sealant, a TFT substrate, and anopposing substrate, respectively, and reference numerals 35 and 41 eachrepresent a marker. A closed loop is formed with the sealant 32, and theliquid crystal 33 is dripped once or multiple times therein by the head43. The barrier layer 34 is provided so that a reaction of the sealant32 and the liquid crystal 33 at that time is prevented. Subsequently,the TFT substrate 30 and the opposing substrate 20 are sealed togetherin a vacuum, and ultraviolet curing is carried out so as to be in astate of being filled with the liquid crystal. Needless to say, achemical solution application apparatus of the present invention may beused to drip-inject the liquid crystal instead of a dispenser method.

A connecting portion is formed for connecting a pixel portion formed bythe above process and an external wiring substrate. Under atmosphericpressure or around atmospheric pressure, an insulating layer of theconnecting portion is removed by an ashing treatment using oxygen gas.This treatment is carried out by using oxygen gas and one or a pluralityof hydrogen, CF₄, NF₃, H₂O, and CHF₃. In this process, an ashingtreatment is carried out after sealing using the opposing substrate, inorder to prevent damage and destruction by static electricity; however,when an influence of static electricity is small, the asking treatmentmay be carried out at any time.

Subsequently, a wiring substrate for connection is provided so that thegate electrode layer 703 is electrically connected via an anisotropicconductive layer. The wiring substrate takes on a role of transmittingsignals and electrical potentials from the exterior. Through the aboveprocess, a display panel (liquid crystal display panel) including achannel-etch type switching TFT and a capacitor element is completed.The capacitor element is formed with the capacitor wiring layer 704, thegate insulating layer 705, and the pixel electrode layer 711.

In the present embodiment mode, a single gate structure is described forthe switching TFT; however, a structure may be a multigate structuresuch as a double gate structure.

As shown above, in this embodiment mode, by using a chemical solutionapplication apparatus capable of moving a plurality of nozzlesindividually in applying a base film, a base film with even filmthickness can be formed. As a result, an effect of shutting off acontaminant or the like from a glass substrate can be obtained. Also,when an insulating layer is formed between the substrate and the basefilm, by using the chemical solution application apparatus of thepresent invention, an insulating layer with even film thickness can beformed. As a result, contamination from the glass substrate to asemiconductor film can be prevented even further.

Embodiment Mode 3

By an application of the present invention, a variety of display devicescan be manufactured. In other words, the present invention can beapplied to a variety of electronic appliances in which these displaydevices are incorporated into displaying portions thereof.

As examples of such electronic appliances, video cameras; digitalcameras; projectors; head-mounted displays (goggle type displays); carnavigation systems; car stereos; personal computers; game machines;portable information terminals (such as a mobile computer, a cellularphone and an electronic book); image reproduction devices equipped witha recording medium (specifically, a device which can replay therecording medium such as a digital versatile disc (DVD) and displayimages thereof); and the like can be given. Examples thereof are shownin FIGS. 16A to 16D.

FIG. 16A shows a personal computer, which includes a main body 2101, ahousing 2102, a display portion 2103, a keyboard 2104, an externalconnection port 2105, a pointing mouse 2106, and the like. The displayportion 2103 can be manufactured according to the present invention. Byusing the present invention, film thickness can be made to be evenentirely over each layer; therefore, a highly reliable image can bedisplayed.

FIG. 16B shows an image reproduction device equipped with a recordingmedium (specifically, a DVD player), and includes a main body 2201, ahousing 2202, a display portion A 2203, a display portion B 2204, arecording medium (a DVD and the like) reading portion 2205, operationkeys 2206, speaker portions 2207, and the like. The display portion A2203 mainly displays image information, while the display portion B 2204mainly displays character information. These display portion A 2203 anddisplay portion B 2204 can be manufactured according to the presentinvention. By using the present invention, film thickness can be made tobe even entirely over each layer; therefore, a highly reliable image canbe displayed.

FIG. 16C shows a cellular phone, which includes a main body 2301, anaudio output portion 2302, an audio input portion 2303, a displayportion 2304, operation switches 2305, an antenna 2306, and the like. Byapplying a display device formed according to the present invention tothe display portion 2304, film thickness can be made to be even entirelyover each layer; therefore, a high reliability image can be displayed.

FIG. 16D shows a video camera, which includes a main body 2401, adisplay portion 2402, a housing 2403, an external connection port 2404,a remote control receiver 2405, an image receiving portion 2406, abattery 2407, an audio input portion 2408, an eyepiece 2409, operationkeys 2410, and the like. The display portion 2402 can be formedaccording to the present invention. By applying a display device formedaccording to the present invention to the display portion 2402, filmthickness can be made to be even entirely over each layer; therefore, ahigh reliability image can be displayed.

Embodiment 1

In this embodiment, a manufacturing method of a semiconductor device isdescribed, in which a solution of an aqueous solution including acatalyst element that promotes crystallization is applied evenly andthinly over an amorphous silicon film using a chemical solutionapplication apparatus of the present invention, and then the amorphoussilicon film is crystallized by heating.

FIGS. 4A and 4B show examples of applying the present invention tocrystallization techniques disclosed in Japanese Patent ApplicationLaid-Open No. H7-130652 and Japanese Patent Application Laid-Open No.H8-78329. First, a base film 402 is provided over a substrate 401 thatis fixed to a suction stage 406, and then an amorphous silicon film 403is formed thereover. As the base film 402, a silicon oxide film, asilicon nitride film, or a silicon nitride oxide film that has a filmthickness of 100 to 300 nm can be used. In this embodiment, TEOS(Tetraethyl Orthosilicate) is used as a raw material, and a siliconoxide film is formed to have a film thickness of 200 nm. Note that ifthe substrate 401 has enough flatness like a quartz substrate, the basefilm 402 is not particularly necessary to be provided.

Here, a nickel-containing layer 404 is formed by applying a nickelacetate solution containing nickel of 10 ppm in weight over theamorphous silicon film 403, using a chemical solution applicationapparatus of the present invention (see FIG. 4A). By using the presentinvention, the nickel acetate solution containing nickel can be evenlyapplied over the amorphous silicon film.

Subsequently, a crystalline silicon film 405 is formed by a one hourdehydrogenation process at 500° C. and then carrying out a heattreatment for 4 to 12 hours at 500 to 650° C. (in this embodiment, for 4hours at 550° C.). The crystalline silicon film (also called“polysilicon”) 405 obtained in this manner is formed by an assembly ofstick-like or needle-like crystals, and from a macroscopic perspective,each of the crystals grows with a certain orientation; therefore, anadvantage is that crystal property is uniform.

For the solution used for the application, a solution including anelement such as germanium (Ge), iron (Fe), palladium (Pd), tin (Sn),lead (Pb), cobalt (co), platinum (Pt), copper (Cu), or gold (Au),besides nickel (Ni), may be used.

Further, in this embodiment, a method of introducing a catalyst elementover an amorphous silicon film is described; however, a method ofintroducing the catalyst element under the amorphous silicon film may beemployed. In this case, a solution including the catalyst element may beapplied over a base film using a chemical solution application apparatusof the present invention prior to forming the amorphous silicon film.

In this manner, by using the chemical solution application apparatus ofthe present invention in applying a catalyst element promotingcrystallization, a coating film with even film thickness can be providedat the same time as controlling a usage amount of the catalyst element.As a result, uniform crystallization can be carried out.

Embodiment 2

In this embodiment, an example of forming an insulating film over asurface of an anode of an EL light emitting element, using a chemicalsolution application apparatus of the present invention is describedwith reference to FIGS. 5A and 5B.

First, over a substrate 500, a switching TFT (a thin film transistorfunctioning as a switching element) 502 and a current control TFT (a TFTfunctioning as an element for controlling a current that is supplied toan EL element. Also referred to as a driving TFT) 503 are formed.Detailed manufacturing methods of the TFTs are omitted herein. Note thatas the substrate 500, a substrate having a light transmitting propertysuch as a quartz substrate may be used. Also, a plastic substrate havinga heat resistant property that can resist a treatment temperature ofthis embodiment may be used.

An interlayer insulating film 535 made from an inorganic insulatingmaterial is formed covering the switching TFT 502 and the currentcontrol TFT 503, so as to have an average film thickness of 1.0 to 2.0μm. As the inorganic insulating material, a silicon oxide film or asilicon oxynitride film may be formed using a known sputtering method orplasma CVD method. Further, in a case of using a silicon nitride oxidefilm, it may be formed by a plasma CVD device using SiH₄ and N₂O asmaterial gases under the following film forming conditions: pressure of40 Pa, substrate temperature of 400° C., an RF output of 100 W, and flowrates of the material gases are to be 4 sccm for SiH₄ and 400 sccm forN₂O.

Subsequently, the interlayer insulating film is polished and planarizedby a technique called a CMP (chemical mechanical polish) method. A CMPmethod is a method of chemically or mechanically planarizing a surfaceof a processing object. The CMP method is a method in which in general,an abrasive cloth or a polishing pad (in this specification, hereinaftercalled a “pad” as a collective term) is attached to a platen (polishingplate), and then rotating or rocking each of the platen and theprocessing object while supplying a slurry between the processing objectand the pad, so that a surface of the processing object is polished by acompound effect of a chemical effect and mechanical polishing. In thisembodiment, after forming the interlayer insulating film 535, theinterlayer insulating film 535 is polished by the CMP method. Theslurry, the pad, and a CMP apparatus used in the CMP method can be thosethat are known, and a polishing method can also be a known method. Notethat after a planarization treatment process by the CMP method iscompleted, an average film thickness of the interlayer insulating film535 is made to be about 1.0 to 2.0 μm. Further, an insulating film madeof a silicon nitride film or a DLC (Diamond Like Carbon) film may beprovided over the interlayer insulating film 535 for which theplanarization treatment is carried out. In this manner, by forming aninsulating film made of a silicon nitride film or a DLC film, it can beconsidered that an alkali metal used when forming a light emittingelement can be prevented from penetrating to a TFT side through theinterlayer insulating film.

Subsequently, a resist mask in a prescribed pattern is formed, and acontact hole is formed so as to reach an impurity region that is asource region or a drain region, formed in a semiconductor layer of eachTFT. The contact hole is formed by a dry etching method.

Then, wirings 536 to 539 are formed by forming a conductive metal filmby a sputtering method or a vacuum evaporation method, and then etchingthe metal film using a mask. Although not shown in a figure, in thisembodiment, these wiring are formed with a laminated film of a Ti filmhaving a film thickness of 50 nm and an alloy film (an alloy film of Aland Ti) having a film thickness of 500 nm.

Subsequently, a transparent conductive film is formed thereover with athickness of 80 to 120 nm and then etched to form an anode 543 (pixelelectrode) (see FIG. 5A). Note that in this embodiment, as a transparentelectrode, a transparent conductive film in which zinc oxide (ZnO) of 2to 20 wt % composition is mixed in an indium tin oxide (ITO) film orindium oxide is used.

Also, by forming the anode 543 so as to be in contact and to beoverlapped with the drain wiring 538, an electrical connection betweenthe anode 543 and a drain region of the current control TFT. Here, aheating treatment at 180 to 350° C. may be carried out for the anode543.

Subsequently, a second interlayer insulating film is formed over theanode 543, and by etching the second interlayer insulating film, apartition (bank) 546 having an opening portion in a position thatcorresponds to a pixel (light emitting element) is formed. In thisembodiment, the bank 546 is formed using a resist. A thickness of thebank 546 is to be about 1 μm, and a region covering a potion where thewiring and the anode is in contact is formed to be slanted.

Note that in this embodiment, a film made from a resist is used as thebank 546; however, depending on the circumstance, polyimide, polyamide,acrylic, BCB (benzocyclobutene), a silicon oxide film, or the like canalso be used. For the bank 546, either an organic substance or aninorganic substance may be used as long as it is a substance having aninsulating property. Note that when the bank 546 is formed using aphotosensitive acrylic film, it is preferable to carry out a heatingtreatment at 180 to 350° C. after etching a photosensitive acrylic film.Further, when the bank 546 is formed using a non-photosensitive acrylic,it is preferable to etch after carrying out a heating treatment at 180to 350° C. to form the bank.

Subsequently, a swabbing treatment is carried out on a surface of theanode (electrode) 543. Note that in this embodiment, by swabbing thesurface of the anode 543 using a porous sponge (typically made of PVA(polyvinyl alcohol), nylon, or the like) in which a surfactant (weaklyalkaline) is included, planarization of the anode 543 surface andremoval of particles stuck to the surface is carried out. As a cleaningliquid for when the particles are removed, purified water is used, and arotation speed of an axis to which the porous sponge is wrapped aroundis to be 100 to 300 rpm, and push-in value is to be 0.1 to 1.0 mm. Notethat as a cleaning mechanism, a cleaning apparatus having a roll brush(made of PVA) that rotates around an axis line parallel to a substratesurface and touches the substrate surface may be used, as well as acleaning apparatus having a disk brush (made of PVA) that rotates aroundan axis line perpendicular to a substrate surface and touches thesubstrate surface.

Subsequently, a third insulating film 547 is formed covering the bank546 and the anode 543. The third insulating film 547 is formed with anorganic resin film of polyimide, polyamide, polyimide amide, or the likeby a chemical solution application apparatus of the present invention,so as to have a film thickness of 1 to 5 nm. By using the chemicalsolution application apparatus of the present invention in applying theorganic resin film, a coating film having an even film thickness can beprovided while suppressing a usage amount of the resin film. By formingthe third insulating film 547 to have an even film thickness, cracks andthe like on a surface of the anode 543 can be covered up, anddeterioration of a light emitting element can be prevented.

Next, a light emitting element 550 is formed by forming an organiccompound layer 548 and a cathode 549 over the third insulating film 547by an evaporation method (FIG. 5B). Note that although an MgAg electrodeis used as the cathode 549 of the light emitting element 550 in thisembodiment, another known material may be used. Note that the organiccompound layer 548 is formed by combining and laminating a plurality oflayers such as a hole injecting layer, a hole transporting layer, anelectron transporting layer, an electron injecting layer, and a bufferlayer in addition to a light emitting layer. Note that in thisembodiment, the organic compound layer 548 and the cathode 549 areformed over the anode 543; however, the organic compound layer 548 andthe anode 543 may be provided over the cathode 549. The same applies toanother embodiment.

Embodiment 3

In this embodiment, an example of using a chemical solution applicationapparatus of the present invention to form a light emitting layer usedin a light emitting element is described.

First, a typical structure of a light emitting element is shown in FIG.6. An anode 601, a light emitting layer 602, and a cathode 603 arelaminated over a substrate 600. It is acceptable as long as the lightemitting layer 602 includes at least a light emitting organic compound,and can be formed using a low molecular compound, a high molecularcompound (polymer), as well as a medium molecular compound such as anolygomer or a dendrimer, or an inorganic compound. For the lightemitting organic compound also, a low molecular compound, a highmolecular compound (polymer), as well as a medium molecular compoundsuch as an olygomer or a dendrimer can be used.

In FIG. 6 of this embodiment, the light emitting layer is constituted bya hole injecting layer 611, a hole transporting layer 612, a layer 613including a light emitting organic compound, an electron transportinglayer 614, and an electron injecting layer 615; however, it is notnecessarily limited to this structure. Note that the hole injectinglayer is a layer showing a function of receiving holes from the anode,and the hole transporting layer is a layer showing a function oftransferring holes to the layer including a light emitting organiccompound. Further, the electron injecting layer is a layer showing afunction of receiving electrons from the cathode, and the electrontransporting layer is a layer showing a function of transferringelectrons to the layer including a light emitting organic compound.

First, materials that can be used for each layer is specifically shownas examples. However, materials that can be applied to the presentinvention are not limited to these.

As a hole injecting material that can be used for the hole injectinglayer, a phthalocyanine based compound is effective, such asphthalocyanine (abbreviation: H₂-Pc), copper phthalocyanine(abbreviation: Cu-Pc), or vanadyl phthalocyanine (abbreviation: VOPc).Also, a material to which chemical doping is done on a conductive highmelecular compound is also available, and polyethylenedioxythiophene(abbreviation: PEDOT) doped with polystyrene sulfonate (abbreviation:PSS), polyaniline (abbreviation: Pani) or the like can also be used.Further, a thin film of an inorganic semiconductor such as molybdenumoxide (MoO_(x)), vanadium oxide (VO_(x)), or nickel oxide (NiO_(x)); oran ultra thin film of an inorganic insulator such as aluminum oxide(Al₂O₃) is also effective. Furthermore, an aromatic amine compound suchas 4,4′,4″-tris(N,N-diphenyl-amino)-triphenylamine (abbreviation:TDATA), 4,4′,4″-tris[N-(3-methylphenyl)-N-phenyl-amino]-triphenylamine(abbreviation: MTDATA),N,N′-bis(3-methylphenyl)-N,N′-diphenyl-1,1′-biphenyl-4,4′-diamine(abbreviation: TPD), 4,4′-bis[N-(1-naphthyl)-N-phenyl-amino]-biphenyl(abbreviation: α-NPD), or4,4′-bis[N-(4-(N,N-di-m-tolylamino)phenyl)-N-phenylamino]biphenyl(abbreviation: DNTPD) can also be used. Also, a substance showing anacceptor property with respect to the aromatic amine compounds may beadded; specifically, a material in which2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (abbreviation:F₄-TCNQ) which is an acceptor is added to VOPc, or a material in whichMoO_(x) which is an acceptor is added to α-NPD, may be used.

By using a chemical solution application apparatus of the presentinvention for applying the hole injecting material, a coating film ofthe hole injecting material with an even thickness can be obtained,which has a small film thickness distribution over the entire anode.Also, since a chemical solution can be discharged into an optimalpattern by a plurality of nozzles, use efficiency can be improved bycutting down on waste of a chemical solution.

As a hole transporting material that can be used for the holetransporting layer, an aromatic amine compound is optimal, and theaforementioned TDATA, MTDATA, TPD, α-NPD, DNTPD and the like can beused.

By using a chemical solution application apparatus of the presentinvention for applying the hole transporting material, a coating film ofthe hole transporting material with an even thickness can be obtained,which has a small film thickness distribution over the entire holeinjecting layer. Also, since a chemical solution can be discharged intoan appropriate pattern by a plurality of nozzles, use efficiency can beimproved by cutting down on waste of a chemical solution.

Subsequently, materials that can be used as the light emitting organiccompound are listed; however, a material is not limited thereto in thispresent invention, and any light emitting organic compound may be used.

For example, blue to blue-green light emission is obtained by dispersinga guest material such as perylene, 2,5,8,11-tetra-t-butylperylene(abbreviation: TBP) or 9,10-diphenylanthracene in an appropriate hostmaterial. In addition, blue to blue-green light emission can be obtainedby a styrylarylene derivative such as4,4′-bis(2,2-diphenylvinyl)biphenyl (abbreviation: DPVBi), or ananthracene derivative such as 9,10-di-2-naphthylanthracene(abbreviation: DNA) or 9,10-bis(2-naphthyl)-2-t-butylanthracene(abbreviation: t-BuDNA). Further, a polymer such aspoly(9,9-dioctylfluolene) may be used.

For example, blue-green to green light emission is obtained bydispersing a guest material such as a coumarin dye such as coumarin 30or coumarin 6;bis[2-(4,6-difluorophenyl)pyridinato-N,C2′](picolinato)iridium(abbreviation: FIrpic);bis(2-phenylpyridinato-N,C2′)(acetylacetonato)iridium (abbreviation:Ir(ppy)₂(acac)) or the like in an appropriate host material. Inaddition, blue-green to green light emission can be obtained bydispersing a high concentration of perylene or TBP mentioned above, 5 wt% or more, in an appropriate host material. Also, it can be obtainedfrom a metal complex such as BAlq, Zn(BTZ)₂, orbis(2-methyl-8-quinolinolato)chlorogallium (Ga(mq)₂Cl). In addition, apolymer such as poly (p-phenylenevinylene) may be used.

For example, yellow to orange light emission is obtained by dispersing aguest material such as rubrene,4-(dicyanomethylene)-2-[p-(dimethylamino)styryl]-6-methyl-4H-pyran(abbreviation: DCM1),4-(dicyanomethylene)-2-methyl-6-(9-julolidyl)ethynyl-4H-pyran(abbreviation: DCM2), bis[2-(2-thienyl)pyridinato]acetylacetonatoiridium (Ir(thp)₂(acac)), bis -(2-phenylquinolinato)acetylacetonatoiridium (Ir(pq)₂(acac)), or the like in an appropriate host material. Inaddition, yellow to orange light emission can be obtained from a metalcomplex such as bis(8-quinolinolato)zinc (abbreviation: Znq₂) orbis[2-cinnamoyl-8-quinolinolato)zinc (abbreviation: Znsq₂). In addition,a polymer such as poly(2,5-dialkoxy-1,4-phenylenevinylene) may be used.

For example, orange to red light emission can be obtained by dispersinga guest material such as4-(dicyanomethylene)-2,6-bis[p-(dimethylamino)styryl]-4H-pyran(abbreviation: BisDCM),4-(dicyanomethylene)-2,6-bis[2-(julolidin-9-yl)ethynyl]-4H-pyran(abbreviation: BisDCJ),4-(dicyanomethylene)-2-methyl-6-(9-julolidyl)ethynyl-4H-pyran(abbreviation: DCM2), bis[2-(2-thienyl)pyridinato]acetylacetonatoiridium (Ir(thp)₂(acac)), bis-(2-phenylquinolinato)acetylacetonatoiridium (Ir(pq)₂(acac)),bis[2-(2′-benzothienyl)pyridinato-N,C3′](acetylacetonato) iridium(abbreviation: Ir(btp)₂(acac)), or the like in an appropriate hostmaterial. In addition, orange to red light emission can be obtained froma metal complex such as bis(8-quinolinolato)zinc (abbreviation: Znq₂) orbis(2-cinnamoyl-8-quinolinolato)zinc (abbreviation: Znsq₂). Further, apolymer such as poly(3-alkylthiophene) may be used.

In addition, among the light emitting organic compounds mentioned above,it is particularly preferable to use a phosphorescent material such asFlrpic, Ir(ppy)₂(acac), Ir(thp)₂(acac), Ir(pq)₂(acac), orIr(btp)₂(acac). Since a current amount is increased with time in a lightemitting element to which the present invention is applied, increase inpower consumption is large. However, when the phosphorescent material isused, power consumption can be reduced typically.

As the appropriate host material in the aforementioned structures, ahost material which has a shorter wavelength than the light emittingorganic compound or one which has a large energy gap is acceptable.Specifically, a hole transporting material or an electron transportingmaterial typified by the foregoing examples can be appropriatelyselected. Also, 4,4′-bis(N-carbazolyl)-biphenyl (abbreviation: CBP),4,4′,4″-tris(N-carbazolyl)triphenylamine (abbreviation: TCTA),1,3,5-tris[4-(N-carbazolyl)phenyl]benzene (abbreviation: TCPB), or thelike may be used.

By using a chemical solution application apparatus of the presentinvention for applying the light emitting organic compound, a coatingfilm of the material that can be used as the light emitting organiccompound can be obtained with an even thickness, and also with a smallfilm thickness distribution over an entire hole transporting layer.Also, since a chemical solution can be discharged into an appropriatepattern by a plurality of nozzles which are variable individually, useefficiency can be improved by cutting down on waste of a chemicalsolution.

As an electron transporting material that can be used for the electrontransporting layer, a metal complex such astris(8-quinolinolato)aluminum (abbreviation: Alq₃),tris(4-methyl-8-quinolinolato)aluminum (abbreviation: Almq₃),bis(10-hydroxybenzo[h]-quinolinato)beryllium (abbreviation: BeBq₂),bis(2-methyl-8-quinolinolato)-(4-phenylphenolato)-aluminum(abbreviation: BAlq), bis[2-(2-hydroxyphenyl)benzoxazolato]zinc(abbreviation: Zn(BOX)₂), bis[2-(2-hydroxyphenyl)benzothiazolato]zinc(abbreviation: Zri(BTZ)2), can be given. Further, other than a metalcomplex, an oxadiazole derivative such as2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation:PBD), or 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazole-2-yl]benzene(abbreviation: OXD-7); a triazole derivative such as3-(4-tert-butylphenyl)-4-phenyl-5-(4-biphenylyl)-1,2,4-triazole(abbreviation: TAZ),3-(4-tert-butylphenyl)-4-(4-ethylphenyl)-5-(4-biphenylyl)-1,2,4-triazole(abbreviation: p-EtTAZ), or the like; an imidazole derivative such as2,2′,2″-(1,3,5-benzenetriyl)-tris[1-phenyl-1H-benzoimidazole](abbreviation: TPBI); a phenanthroline derivative such asbathophenanthroline (abbreviation: BPhen), or bathocuproin (BCP); can beused.

By using a chemical solution application apparatus of the presentinvention for applying the electron transporting layer, a coating filmof the electron transporting material with an even thickness can beobtained, that has a small film thickness distribution over the layerincluding a light emitting organic compound. Also, in the presentinvention, since a chemical solution can be discharged into an optimalpattern by a plurality of nozzles which are variable individually, useefficiency can be improved by cutting down on waste of a chemicalsolution.

As an electron injecting material that can be used for the electroninjecting layer, the aforementioned electron transporting material ofAlq₃, Almq₃, BeBq₂ , BAlq, Zn(BOX)₂, Zn(BTZ)₂, PBD, OXD-7, TAZ, p-EtTAZ,TPBI, BPhen, BCP, or the like can be used. In addition, an ultra thinfilm of an insulator like an alkali metal halide such as LiF or CsF; analkali earth halide such as CaF₂; or an alkali metal oxide such as Li₂Ois often used. Also, an alkali metal complex such as lithiumacetylacetonate (abbreviation: Li(acac)) or 8-quinolinolato-lithium(abbreviation: Liq) is also effective. Further, a substance showing adonor property with respect to the electron injecting material may beadded, and as a donor, an alkali metal, an alkali earth metal, a rareearth metal or the like can be used. Specifically, BCP to which lithiumwhich is a donor is added, or Alq₃ to which lithium which is a donor isadded, can be used.

By using a chemical solution application apparatus of the presentinvention for applying the electron injecting material, a coating filmof the electron injecting material with an even thickness can beobtained, which has a small film thickness distribution over the entireelectron transporting layer. Also, since a chemical solution can bedischarged into an appropriate pattern by a plurality of nozzles whichare variable individually, use efficiency can be improved by cuttingdown on waste of a chemical solution.

As a material constituting the anode 601 in a light emitting element, aconductive material with a large work function is preferably used. Also,in a case of extracting light from the anode 601, a transparentconductive material such as indium tin oxide (ITO), indium zinc oxide(IZO), zinc oxide (ZnO), or indium tin oxide to which silicon oxide isadded, may be used. Further, if the anode 601 is to have a lightshielding property, in addition to a single layer film of TiN, ZrN, Ti,W, Ni, Pt, Cr or the like; a lamination of a titanium nitride film and afilm mainly containing aluminum; a three layer structure of a titaniumnitride film, a film mainly containing aluminum, and a titanium nitridefilm; or the like can be used. Alternatively, a method may be that oflaminating the foregoing transparent conductive material over areflective electrode of Ti, Al or the like.

Also, as a material constituting the cathode 603, a conductive materialwith a small work function is preferably used. Specifically, in additionto an alkali metal such as Li or Cs, an alkali earth metal such as Mg,Ca, or Sr, or an alloy including thereof (such as Mg:Ag or Al:Li), arare earth metal such as Yb or Er can also be used to form the cathode603. Also, another conductive material (for example aluminum or thelike) may be laminated over the conductive material. Further, in a caseof using an electron injecting layer of LIF, CsF, CaF₂, Li₂O, or thelike, an ordinary conductive thin film such as aluminum can be used.Furthermore, in a case of making an cathode 603 side as a lightextraction direction, a lamination structure of an ultra thin filmincluding an alkali metal such as Li or Cs and an alkali earth metalsuch as Mg, Ca, or Sr; and a transparent conductive film (such as ITO,IZO, or ZnO) may be used. Alternatively, a structure may be that oflamination of a layer to which the aforementioned substance (such as analkali metal or an alkali earth metal) showing a donor property withrespect to the electron transporting material is added, and atransparent conductive film (ITO, IZO, ZnO or the like). Specifically,ITO may be laminated over a layer in which lithium which is a donor isadded to BCP, or a layer in which lithium which is a donor is added toAlq₃.

In manufacturing a light emitting element in the above manner, achemical solution application apparatus of the present invention can beused to form each of the layers in the light emitting layer 602. As aresult, since a chemical solution can be discharged into an appropriatepattern by a plurality of nozzles which are mobile individually andindependently, use efficiency can be improved by cutting down on wasteof a chemical solution.

This application is based on Japanese Patent Application serial no.2005-170921 filed in Japan Patent Office on Jun. 10, 2005, the entirecontents of which are incorporated by reference.

1. A method for manufacturing a display device comprising: holding asubstrate on a stage; discharging a chemical solution to the substratethrough a plurality of nozzles; rotating the substrate on the stageduring discharging the chemical solution; and moving each nozzle of theplurality of nozzles, wherein one nozzle of the plurality of nozzles iscapable of being moved independently from the other nozzles.
 2. Themethod for manufacturing the display device according to claim 1,wherein one nozzle of the plurality of nozzles is capable of being movedin either a horizontal direction or a vertical direction with respect toa surface of the substrate.
 3. The method for manufacturing the displaydevice according to claim 1, wherein each nozzle of the plurality ofnozzles is held by a guide rail.
 4. The method for manufacturing thedisplay device according to claim 3, wherein the guide rail is arrangedin a matrix form.
 5. The method for manufacturing the display deviceaccording to claim 1, wherein the display device is a liquid crystaldisplay device.
 6. A method for manufacturing the display devicecomprising: holding a substrate on a stage; discharging a chemicalsolution to the substrate through a plurality of nozzles; rotating thesubstrate on the stage during discharging the chemical solution;controlling an amount of the chemical solution to be discharged from theplurality of nozzles; and moving each nozzle of the plurality ofnozzles, wherein one nozzle of the plurality of nozzles is capable ofbeing moved independently from the other nozzles, and wherein the amountof the chemical solution to be discharged from one nozzle of theplurality of nozzles is controlled independently from the other nozzles.7. The method for manufacturing the display device according to claim 6,wherein one nozzle of the plurality of nozzles is capable of being movedin either a horizontal direction or a vertical direction with respect toa surface of the substrate.
 8. The method for manufacturing the displaydevice according to claim 6, wherein each nozzle of the plurality ofnozzles is held by a guide rail.
 9. The method for manufacturing thedisplay device according to claim 8, wherein the guide rail is arrangedin a matrix form.
 10. The method for manufacturing the display deviceaccording to claim 6, wherein the amount of the chemical solution iscapable of being controlled by a control portion.
 11. The method formanufacturing the display device according to claim 6, wherein thedisplay device is a liquid crystal display device.
 12. A method formanufacturing the display device comprising: holding a substrate on astage; discharging a chemical solution to the substrate through aplurality of nozzles; rotating the substrate on the stage duringdischarging the chemical solution; and moving each nozzle of theplurality of nozzles, wherein one nozzle of the plurality of nozzles iscapable of being moved independently from the other nozzles, and whereina cup and a cup lid are set so that the chemical solution that hasbecome a mist is prevented from reattaching to the substrate, whenrotating the substrate on the stage.
 13. The method for manufacturingthe display device according to claim 12, wherein one nozzle of theplurality of nozzles is capable of being moved in either a horizontaldirection or a vertical direction with respect to a surface of thesubstrate.
 14. The method for manufacturing the display device accordingto claim 12, wherein each nozzle of the plurality of nozzles is held bya guide rail.
 15. The method for manufacturing the display deviceaccording to claim 14, wherein the guide rail is arranged in a matrixform.
 16. The method for manufacturing the display device according toclaim 12, wherein the display device is a liquid crystal display device.17. A method for manufacturing the display device comprising: holding asubstrate on a stage; discharging a chemical solution to the substratethrough a plurality of nozzles; rotating the substrate on the stageduring discharging the chemical solution; controlling an amount of thechemical solution to be discharged from the plurality of nozzles; andmoving each nozzle of the plurality of nozzles, wherein one nozzle ofthe plurality of nozzles is capable of being moved independently fromthe other nozzles, wherein the amount of the chemical solution to bedischarged from one nozzle of the plurality of nozzles is controlledindependently from the other nozzles, and wherein a cup and a cup lidare set so that the chemical solution that has become a mist isprevented from reattaching to the substrate, when rotating the substrateon the stage.
 18. The method for manufacturing the display deviceaccording to claim 17, wherein one nozzle of the plurality of nozzles iscapable of being moved in either a horizontal direction or a verticaldirection with respect to a surface of the substrate.
 19. The method formanufacturing the display device according to claim 17, wherein eachnozzle of the plurality of nozzles is held by a guide rail.
 20. Themethod for manufacturing the display device according to claim 19,wherein the guide rail is arranged in a matrix form.
 21. The method formanufacturing the display device according to claim 17, wherein theamount of the chemical solution is capable of being controlled by acontrol portion.
 22. The method for manufacturing the display deviceaccording to claim 17, wherein the display device is a liquid crystaldisplay device.